The present invention relates, in general, to semiconductor processing and, more particularly, to semiconductor processing utilizing thick film spin-on glass (SOG).
The use of spin-on glass is well known in the art of semiconductor processing but is limited in usable thickness. Presently, the maximum thickness utilized for spin-on glass is approximately 2000 Angstroms. Using films thicker than this cause the glass layer to become highly stressed and result in cracks developing during processing. If a thicker glass layer is desired, it would have to be put down in multiple layers separated by chemical vapor deposition (CVD) oxide. Even with using multiple layers, it has been found that the maximum thickness is 4000 Angstroms, or two layers of 2000 Angstroms each separated by the CVD layer. The reason for this limitation is that the lower SOG layer cannot support more than one more SOG layer during processing.
Therefore, it is an object of the present invention to provide a process of forming semiconductors that overcomes the above deficiencies.
A further object of the present invention is to provide a process of utilizing spin-on glass in semiconductor processing that permits use of thick films.
Another object of the present invention is to provide a process of utilizing spin-on glass in semiconductor processing that will permit the use of more than two layers of spin-on glass.
The above and other objects and advantages of the present invention are provided by the process described herein.